Hi all, Rcv'd this, this morning. Some interesting points
re the discussion coax vs. twin line for amateur HF use.
I suppose "open-wire" ladder line is what is being criticized
below. Open wire line, with a spacer only every now and
then is certainly prone to uneven wire spacing, hence
imbalance and radiation. Will be interesting to monitor
my long run of poly-insulated twin lead to see what
impact water and mold build up out here will cause.
73, Jim, KH7M
-----Original Message-----
From: warren munro <wmunro@lava.net>
To: jreid@aloha.net <jreid@aloha.net>
To: <towertalk@contesting.com>
Date: Monday, July 13, 1998 8:45 AM
Subject: devil's advocate hi hi
>Hi Jim: On the subject of coax versus open-line feeders, I remember back
>around 1970 when I worked part-time for local Channel 13 (title Transmitter
>Technician hi hi). The Chief Engineer was a very sharp New Zealander, and
>we got into exactly the same discussion as yours, and I espoused the same
>arguments as you.
>
>He disagreed and said go coax or hard-line in almost evry HF case because:
>
>1) Open wire very prone to feed-line radiation, destroying antenna pattern
>and possibly affecting gian.
>
>2) Open-wire feedkline losses are much higher in actual practice than
>those shown "in the book". Wait for yours to get wet, crusty with mold,
>etc. etc. and then see what the performance is.
>
>3) Necessity for more baluns, connections, sky-hooks, and general doo-dads
>when using open-wire-feed greatly increases the Murphy factor.
>
>4) HF antennas all designed for 50 ohms.
>
>5) Simplicity and durability of coax is hard to beat.
>
>Just thought there should be one voice offering an "alternate school" hi
hi.
>
>73, Warren KH6WM
>
>
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